Sharpener for planing machine cutter-block blades



2 Sheets-Sheet l D. E. BURGESS SHARPENER FOR PLANING MACHINE CUTTERBLOCK BLADES June 12, 1956 Filed Nov. 18, 1952 June 12, 1956 D u ss2,749,677

SHARPENEIR FOR PLANING MACHINE CUTTER BLOCK BLADES Filed Nov. 18, 1952 2Sheets-Sheet 2 Fig.

@0214 701 Fee bu Qess United States Patent SHARPENER FOR PLANING MACHINECUTTER-BLOCK BLADES Donald Eric Burgess, New Southgate, London, EnglandApplicafion November 18, 1952, Serial No. 321,196

Claims priority, application Great Britain November 22, 1951 1 Claim.(Cl. 51173) This invention relates to devices for grinding, sharpeningor honing and more especially to an electrically operated deviceparticularly suitable for sharpening the blades of planing machines.

The invention consists of a hand grinding, sharpening or honing devicecomprising a motor-driven grinding, sharpening or honing wheel and aframe by which the grinding, sharpening or honing wheel may be held ingrinding, sharpening or honing relation to a cutter blade on a cutterblock of a planing or like machine.

Conveniently the grinding, sharpening or honing wheel is held by theframe resting on the cutter block and is checked from rotatingtherearound.

Conveniently also, the frame is made adjustable, e. g. for differentdiameters of cutter block, or angles of grinding etc.

Also the position of the grinding, sharpening or honing wheel inrelation to the frame may be made to be finely adjustable in thedirection of the axle of rotation of the wheel, e. g. by a micrometerscrew adjustment.

In operation the hand device or tool is held in its set position by handpressure and is pushed in the axial direction of the cutter along theblade which is to be ground, sharpened or honed.

An embodiment of the invention will be described with reference to theaccompanying drawings.

Figure 1 is an end elevation;

Figure 2 a side elevation;

Figure 3 is a longitudinal section of the micrometer adjuster; and

Figure 4 shows the method of adjustment for different cutter blockdiameters.

In the embodiment an electric motor 1 is supported on a frame 2 and overa V-pulley 3 fitted on its output shaft and a V-belt 4, drives agrinding wheel 5.

The grinding wheel 5 is carried on a shaft 5a supported in ball bearingraces 6 located in a cylindrical shell 7 which slides but does notrotate on a cylindrical support 8.

The position of the grinding wheel is adjusted by means of a micrometerscrew 9 the position of which is controlled by a knurled head 10 mountedso that it may rotate in relation to the support 8 but cannot moveaxially in relation thereto.

The frame 2 carries an extension frame 11 having a hinged part 11asecured thereto by which the device can be rested on a cutter block ofany diameter within a range (see Figure 4).

The axis of the grinding wheel is set in relation to the frame so thatwhen the frame rests on a cutter block the grinding wheel axis isdisplaced in a plane therethrough and parallel to the axis of the cutterblock by around 1.

The frame 11 also carries a slideway or an insert 12 which has slidablymounted therein a T-piece 13. The head of the T-piece is bevelled at 13ato keep it clear of the cutter block and the T-piece is placed with itsedge immediately behind the back edge of the cutter blade 15 in thecutter block 14.

Thus by anti-clockwise hand pressure in relation to the view shown inFigure l the grinding wheel 5 may be held up to the blade 15 and thegrinding wheel adjusted to sharpen it.

The device may then be slid along in the axial direction of the cutterblock to complete the sharpening process over the whole cutter.

Other cutter blades in the block may be similarly sharpened and all willthen be at the same position, i. e. with the same amount of cutter bladestanding out of the cutter block.

Thus the blades when ground in position in the cutter blade will be setfor height and angle and parallel to their length Whereas when groundaway from the cutter blade the operation of setting them convenientlyback in the cutter blade may be a long and tedious one and furthermorethe resulting deviations as between the setting of the different bladesof the cutters may be considerable.

Various modifications may be made within the scope of the invention.Thus the device may be used in association with a guide rail secured tothe table of a planer.

I claim:

A portable device for grinding the straight edges of the cutter bladesmounted upon the rotary cylindrical cutter block of a woodworkingmachine, said device comprising a frame adapted to rest upon thecircumference of the cutter block and having two parallel, spaced-apartbars adapted to rest on the cutter block at opposite sides of a blade,whereby the frame is freely shiftable angularly about the circumferenceof the cutter block, a hinged connection between one of said bars andthe frame to afford pivotal adjustment about an axis parallel with thebars to permit the device to be used upon cutter blocks of differentdiameters, a grinding wheel of the disc type having a radial operatingface mounted upon the frame with said radial operating face disposed ina plane approximately tangential to the cutter block, an electric motorsecured to the frame adjacent the grinding wheel and drivingly connectedto the grinding wheel, a cylindrical support upon the frame, a shellslidable longitudinally within the cylindrical support, a shaftsuspended by the shell and supporting the grinding wheel for rotationand projecting outwardly through the lower end of the cylindricalsupport, a screw afixed to the shell and projecting outwardly throughthe upper end of the cylindrical support, a nut threaded on the screwand abutting the upper end of the cylindrical support to affordmicrometrie adjustment of the operating face of the grinding wheel in adirection to and from a cutter blade, a slideway upon the frame, and aslidepiece mounted for slidable adjustment in the slideway, saidslidepiece being disposed below and approximately parallel to theoperating face of the grinding wheel and having one end engageable withthe back edge of the blade in the cutter block for checking rotation ofthe frame around the cutter block in one direction whereby to hold thefiat operating face of the grinding wheel in sharpening relation to theblade.

References Cited in the file of this patent UNITED STATES PATENTS1,085,876 Redden Feb. 3, 1914 1,443,150 Schimmel Jan. 23, 1923 2,338,995Burns Jan. 11, 1944 2,549,147 Walters Apr. 17, 1951 FOREIGN PATENTS258,375 Switzerland May 2, 1949 501,975 Belgium Apr. 14, 1951 804,070Germany Apr. 16, 1951

